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Subject[PATCH V2 3/4] ARM64 LPC: support serial based on low-pin-count
Date
From: "zhichang.yuan" <yuanzhichang@hisilicon.com>

On Hip06 platform, a 16550 compatible UART is connected to low-pin-count and
controlled through the LPC I/O cycles. This patch drives the UART port with
the specific serial in/out function pair based on the indirect-IO mechanism
introduced by Hip06 LPC driver.

Signed-off-by: zhichang.yuan <yuanzhichang@hisilicon.com>
---
.../devicetree/bindings/serial/hisi-lpc-uart.txt | 50 ++++++++++
drivers/tty/serial/8250/8250_hisi_lpc.c | 104 +++++++++++++++++++++
drivers/tty/serial/8250/Kconfig | 9 ++
drivers/tty/serial/8250/Makefile | 1 +
4 files changed, 164 insertions(+)
create mode 100644 Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt
create mode 100644 drivers/tty/serial/8250/8250_hisi_lpc.c

diff --git a/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt b/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt
new file mode 100644
index 0000000..ff391cc
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt
@@ -0,0 +1,50 @@
+* Hisilicon hip06 UART through low-pin-count
+
+Required properties:
+- compatible : "hisilicon,lpc-uart"
+- reg : offset and length of the I/O port set for the device.
+- indirect-io : identify this device based on the indirect IO mechanism.
+
+Clock handling:
+ The clock rate of this device is same as the 8250 default clock rate, that
+ is 1843200. No need to define the clock rate in device tree.
+
+Note:
+ This device depends on its parent device whose compatible string is
+ "hisilicon,low-pin-count".
+
+ The format of "reg" property follows the I/O space definition in ISA/EISA
+ binding specification linked to:
+ http://www.firmware.org/1275/bindings/isa/isa0_4d.ps
+
+Example:
+
+ uart0: lpc-uart@2f8 {
+ compatible = "hisilicon,lpc-uart";
+ reg = <0x01 0x2f8 0x08>;
+ status = "disabled";
+ };
+
+Example with low-pin-count parent device:
+
+ isa@a01b0000 {
+ compatible = "hisilicon,low-pin-count";
+ #address-cells = <2>;
+ #size-cells = <1>;
+ reg = <0x0 0xa01b0000 0x0 0x1000>;
+ ranges = <0x01 0xe4 0x0 0xe4 0x04>,
+ <0x01 0x2f8 0x0 0x2f8 0x08>;
+
+ ipmi0: bt@e4 {
+ compatible = "ipmi-bt";
+ device_type = "ipmi";
+ reg = <0x01 0xe4 0x04>;
+ status = "disabled";
+ };
+
+ uart0: lpc-uart@2f8 {
+ compatible = "hisilicon,lpc-uart";
+ reg = <0x01 0x2f8 0x08>;
+ status = "disabled";
+ };
+ };
diff --git a/drivers/tty/serial/8250/8250_hisi_lpc.c b/drivers/tty/serial/8250/8250_hisi_lpc.c
new file mode 100644
index 0000000..fbaae89
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_hisi_lpc.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved.
+ * Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
+ * Author: Zou Rongrong <@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/serial_8250.h>
+#include <asm-generic/serial.h>
+#include <linux/of_address.h>
+
+
+static int hslpc8250_probe(struct platform_device *pdev)
+{
+ struct uart_8250_port uart = {};
+ struct uart_port *port = &uart.port;
+ int err = 0;
+ struct resource *iores;
+
+ if (!pdev->dev.parent)
+ return -ENODEV;
+ dev_info(&pdev->dev, "##probe entering\n");
+
+ iores = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!iores) {
+ dev_err(&pdev->dev, "can not find the IO0\n");
+ return -ENXIO;
+ }
+ port->iobase = iores->start;
+
+ port->irq = 0;
+ port->flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
+ port->dev = &pdev->dev;
+ port->iotype = UPIO_PORT;
+ port->regshift = 0;
+ port->uartclk = BASE_BAUD * 16;
+
+ spin_lock_init(&port->lock);
+
+ err = serial8250_register_8250_port(&uart);
+ if (err < 0) {
+ dev_err(&pdev->dev, "register uart FAIL(%d)!\n", -err);
+ return err;
+ }
+
+ platform_set_drvdata(pdev, (void *)&err);
+ dev_info(&pdev->dev, "##probing OK(%d)\n", err);
+ return 0;
+}
+
+static int hslpc8250_remove(struct platform_device *pdev)
+{
+ int line = *((int *)platform_get_drvdata(pdev));
+
+ serial8250_unregister_port(line);
+
+ return 0;
+}
+
+
+static const struct of_device_id hs8250_of_match[] = {
+ { .compatible = "hisilicon,lpc-uart" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, hs8250_of_match);
+
+static const struct acpi_device_id hs8250_acpi_match[] = {
+ /*{ "PNP0501", 0 },*/
+ { "HISI1031", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, hs8250_acpi_match);
+
+static struct platform_driver hs_lpc8250_driver = {
+ .driver = {
+ .name = "hisi-lpc-uart",
+ .of_match_table = hs8250_of_match,
+ .acpi_match_table = ACPI_PTR(hs8250_acpi_match),
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .probe = hslpc8250_probe,
+ .remove = hslpc8250_remove,
+};
+
+module_platform_driver(hs_lpc8250_driver);
+
+
+MODULE_AUTHOR("Rongrong Zou");
+MODULE_DESCRIPTION("8250 serial probe module for Hisilicon LPC UART");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("v1.0");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 7c6f7af..c2e42f7 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -246,6 +246,15 @@ config SERIAL_8250_HUB6
To compile this driver as a module, choose M here: the module
will be called 8250_hub6.

+config SERIAL_8250_HISI_LPC
+ tristate "Support Hisilicon Hip0X UART through LPC"
+ depends on SERIAL_8250 !=n && HISILICON_LPC
+ help
+ Say Y here if you have a hip06 board.
+
+ To compile this driver as a module, choose M here: the module
+ will be called 8250_hisi_lpc.
+
#
# Misc. options/drivers.
#
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 367d403..1f2915b 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o
obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554) += 8250_exar_st16c554.o
obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o
+obj-$(CONFIG_SERIAL_8250_HISI_LPC) += 8250_hisi_lpc.o
obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o
obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o
obj-$(CONFIG_SERIAL_8250_OMAP) += 8250_omap.o
--
1.9.1
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